Training cartridge for an automatic rapid-fire weapon

ABSTRACT

The invention relates to a training cartridge for an automatic rapid-fire weapon. Said training cartridge ( 1 ) has a central channel ( 4 ) running therethrough which accommodates a propellant charge ( 6 ) in the rear area of the cartridge ( 1 ) and is closed at the rear by a detonator charge ( 7 ) for the propellant charge ( 6 ). The training cartridge and weapon barrel are configured in such a way that no live ammunition can be fired from said weapon barrel. The channel which is open at the cartridge tip is preferably used during the firing of the training cartridge to receive a mandrel ( 28 ) of a gas choke ( 22 ) which is mounted in the weapon barrel ( 21 ). The propulsion gases which escape through the opening ( 8 ) at the cartridge tip propel the training cartridge backwards towards the weapon bolt and expel said cartridge from said bolt of the rapid-fire weapon. The bolt is simultaneously primed for the next shot.

BACKGROUND OF THE INVENTION

The invention relates to a medium-bore training cartridge for anautomatic rapid-fire weapon and also a system based on such a trainingcartridge and a weapon barrel.

For training purposes, it is necessary to have at one's disposaltraining and maneuver ammunition, the features of which correspond tolive ammunition, at least where rapid-fire weapons are concerned, sothat all functions can run smoothly. It must not be necessary in thisregard to make any essential modifications to the weapon. At the sametime, the training cartridge and any necessary conversion kit for theweapon must be configured in such a way that live ammunition cannotinadvertently be fired whilst shooting with maneuver ammunition.

German Patent No. DE-A-14 53 827 proposes to equip the trainingcartridge with a bore hole, which is closed off above the propellantcharge arranged in the rear area and if necessary in the area near thecartridge tip by a destructible cap. If the cover(s) is (are) correctlydimensioned, the cartridge, when fired, is followed by an initial shockdust, which is sufficient to guarantee a recoil of the barrel when theweapon bolt is reversed. The covers are subsequently destroyed by thepropellant charge and leave the barrel before the cartridge, the speedof which is reduced due to the presence of the continuous bore hole.

This type of training cartridge however does not guarantee to preventlive ammunition being inadvertently fired.

German Patent No. DE-A-37 33 216 discloses a weapon barrel for automaticweapons for the purposes of firing training ammunition, particularlyblank cartridges, whereby a limiting bush is secured near a cartridgebearing and the weapon bolt inside the barrel and a nozzle insert issecured as a gas choke near the muzzle in the front part of the barrel.This limiting bush must be configured so as to prevent a live cartridgebeing fully pushed into the barrel, which ensures that the weapon willremain fully operable in this case. Training ammunition, which is simplymodified to be thinner near the cartridge tip can be inserted so farinto the limiting bush that the cartridge is completely accommodated bythe barrel.

When firing blank cartridges, this barrel, which is preferably ade-commissioned barrel that has been modified for use with liveammunition, is replaced by a barrel suitable for firing live ammunition.The use of a nozzle insert, which if necessary has an adjustable tuyerearea, creates a gas pressure in the barrel that is both necessary andadequate for automatic weapon function when a training cartridge isfired. This gas pressure guarantees both the locking function andejection of the cartridge. The blank cartridge does not leave thebarrel, the bang, smoke and possibly the flash from the muzzle aresimply simulated when the blank cartridge is loaded.

This system can be applied to small-bore training ammunition. It doeshowever require structural modifications to the barrel and the trainingammunition.

Moreover, it is extremely difficult to achieve the gas pressure requiredfor medium-bore rapid-fire weapons with this system. With conventional40 mm training cartridges, gas pressures able to release the weaponbolt, which weighs approximately 7 kg, must be provided.

German Patent No. DE-A1-41 34 505 discloses a small-bore cartridge forsimulated firing using a laser beam, which has a bush with longitudinalbore hole, whereby the external form of the bush corresponds to that ofa standard cartridge case containing a cartridge. Release of a weaponbolt is also not possible with this cartridge.

SUMMARY OF THE INVENTION

The object of the invention is to provide a training cartridge,particularly for large-bore rapid-fire weapons, which allows large gaspressures to be created in the barrel that can release even heavy weaponbolts. A further purpose of a system based on this type of trainingcartridge and its application as a weapon barrel is to create anautomatic rapid fire weapon, which has a reliable function, is simplyconstructed, consists of few components and which is thereforecost-effective to produce.

This object, as well as other objects which will become apparent in thediscussion that follows are achieved, in accordance with the presentinvention, by providing a medium-bore training cartridge, formedium-bore automatic rapid-fire weapon, comprising a continuous centralchannel having a rear area, the channel accommodating a propellantcharge in the rear area and being closed at the rear by a detonatorcharge for the propellant charge. The training cartridge is open at thecartridge tip and has devices for allowing this cartridge, and not alive projectile cartridge, to be inserted into a barrel designed fortraining purposes.

Accordingly, the training cartridge has a continuous central channel,which contains a propellant charge in the rear area of the cartridge andwhich is sealed off at the rear by a detonator charge for the propellantcharge. The channel is open at the cartridge tip. Training cartridge andbarrel both have devices to prevent the insertion of a live cartridge.The open channel of the training cartridge is preferably used for thispurpose. When the training cartridge is fully inserted into the barrel,the mandrel of an insert projects into the barrel in the open end of thechannel, whereby this insert limits the vacant space before the nose ofthe cartridge. The insert can also be equipped with overflow channels.

The mandrel ensures that a live cartridge cannot be inserted instead ofa training cartridge, since this is sealed at its tip to prevent it fromcompletely leaving the barrel. The rapid-fire weapon would be operablein such a case.

After the detonator charge has ignited the propellant charge, e.g. usinga strike pin, the propellant gas disperses vehemently towards the openend of the central channel in the training cartridge, whereby a high gaspressure is rapidly created in the relatively small space betweenpropellant charge and mandrel tip. This pressure rapidly propels thecartridge backwards towards the weapon bolt which is then released.

The diameter of the insert mandrel is preferably smaller than thediameter clearance of the central channel in the cartridge, whichcreates a gap between channel and mandrel through which the propellantgas starts to escape shortly after the propellant charge is ignited andthrough which the overflow channel in the insert acting as a gas chokeruns towards the muzzle of the barrel. Given correct dimensions of themandrel, central channel and gas choke, the same effects as thoseachieved with a live projectile cartridge can be simulated, e.g. flash,bang and smoke.

The training cartridge can essentially be constructed from fourcomponents, namely a cartridge base, a central barrel inserted into thecartridge base that runs longitudinal to the cartridge into which thepropellant charge is loaded, an igniter cap inserted into the cartridgebase for igniting the propellant charge and a single-piece cartridgebody, which surrounds the central barrel from cartridge barrel upwards,but it does however leave the central barrel open at the cartridge tip.The cartridge body is preferably produced from injection-molded plastic.The cartridge base is usually a metal component and should preferably bealuminum or steel; the central pipe should preferably be steel, in orderto be able to withstand the gas pressures occurring when the propellantcharge is ignited.

It is also possible, to cover the nose end of the propellant charge witha destructible cap or rupture disk and/or provide a further nozzle ornozzle arrangement in the central channel, whereby the development ofthe gas pressure created in the barrel can be further optimized afterthe propellant charge has been ignited.

A training cartridge as proposed by the invention does not cause adirect pressure build up behind the training cartridge with simulatedfiring. Instead, the gases created by the propellant charge are fed intothe cartridge over the cartridge tip, so that the gas pressure createdbetween the cartridge tip and the insert in the barrel propels thetraining cartridge to release the weapon bolt.

For a full understanding of the present invention, reference should nowbe made to the following detailed description of the preferredembodiments of the invention as illustrated in the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a training cartridge for a 40 mmrapid-fire weapon as proposed by the invention.

FIGS. 2 to 6 are sequential drawings showing the simulated firing of atraining cartridge, from loading the cartridge through to ejection.

FIG. 7 is a partially cutaway view of a slightly modified trainingcartridge according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown by FIG. 1, training cartridge 1 has a cartridge base 2 ofaluminum, a central steel barrel 4 screwed into a central thread 3 ofthe cartridge base and a cartridge body 5 forming a cup shape from thecartridge base upwards, this cartridge body being a single-pieceinjection-molded plastic component and extending to the front end of thesteel barrel 4. The rear half of the steel barrel 4 is filled withpropellant charge 6, which, with the aid of a striking pin, can beignited by an igniter cap 7 inserted into the cartridge base in the rearof the cartridge. The steel barrel has at its tip a free opening 8, theedge of which lies directly adjacent to the aforementioned cartridgebody 5.

As shown in FIG. 1, central steel barrel 4 can be split at its center bya dividing wall 9, in which a nozzle 10 is provided, which connects thespace around propellant charge 6 with the empty space in the steelbarrel up to opening 8.

FIG. 2 shows a barrel 21 of an automatic rapid-fire weapon. An insert 22is pushed into this barrel from the front end outwards, whereby thisinsert consists of a barrel 23 and a piston 24. Barrel 23 lies flushwith the inside of barrel 21 and is fitted at the end facing piston 24with a limit stop 25, which lies adjacent to the front edge of barrel21. Barrel 23 is held by a spigot nut 26 with a central opening 27,which is screwed into an outer thread of the barrel 21.

Piston 24 has a central mandrel 28, the outer diameter of which issmaller than the clear diameter of steel barrel 4. The length of themandrel is equivalent to a maximum of the distance between opening 8 ofthe steel barrel 4 and the dividing wall 9 in barrel 4.

Several further overflow channels 29 are provided around central mandrel28 in the piston 24.

FIGS. 2 to 7 show the functional sequence of the automatic rapid-fireweapon when used with the training cartridge.

FIG. 2 shows the point in time at which training cartridge 1 is loadedby the bolt in barrel 21: this process causes central mandrel 28 ofinsert 22 to project into central steel barrel 4.

In FIG. 3, training cartridge 1 has completely left the lock and islocated in barrel 21; at this moment in time, igniter cap 7 is ignitedby a strike pin of the lock. The propellant charge 6 is ignited atvirtually the same time.

The propellant gases 31 generated as the charge is combusted, which areschematically illustrated in FIG. 4, disperse towards the cartridgenose, whereby the gas is choked through the gap between central mandrel28 and the width clearance of central barrel 4. The gases flow into thespace that forms a vacant space 30 between the front end of a propellantcharge and the tip of the mandrel. This creates a high gas pressure,which, as indicated in FIG. 4 by the arrow, moves the cartridge backtowards the lock.

The propellant gases, the volume of which has increased in vacant space30 between the cartridge nose and piston 24, escape from free opening 8of the steel barrel and through the gap between mandrel 28 and steelbarrel 4, so that the pressure of these propellant gases, as indicatedin FIG. 5, now acts on the full face of the cartridge and acceleratesthis backwards into the cartridge. The propellant gases then flowthrough overflow channels 29 and escape into the outside air fromcentral opening 27 of spigot nut 26.

At the point in time indicated in FIG. 6, the training cartridge slidescompletely from central mandrel 28 and is transferred back into thebolt, from which point it is subsequently ejected.

By optimizing the dimensions of mandrel diameter 28, diameter clearanceof steel barrel 4, number and diameter of overflow channels 29 and thedistance between piston 24 and insert 22 and where necessary arrangingand dimensioning nozzle 10 in dividing wall 9, the pressure build-up inbarrel 21 can be optimized to force the training cartridge back into thebolt. The gas pressure created initially in a small high pressure spacebetween propellant charge and mandrel tip and the subsequent creation ofanother pressure area between the piston and the entire cross-sectionalarea of the cartridge, the high forces required for the bolt of theautomatic weapon to function are achieved. It is also possible, throughthe stated dimensioning and also of course collecting the propellantcharge at the muzzle of barrel 21 for simulated firing, to imitate theeffects occurring with live ammunition, e.g. flashes, bangs and smoke.

FIG. 7 shows a modified training cartridge. For equivalent elements asillustrated by the design example in FIG. 1, equivalent referencesymbols are used. With this cartridge, propellant charge 6 positioned onthe rear side is covered by a destructible cap or rupture disk 71; thedividing wall with nozzle is omitted. The diameter of the training shotreduces in the nose area, so that a limit stop 72 is created, which thenlies adjacent to a corresponding limit stop 73 of the barrel 21indicated schematically here. In this nose area of the cartridge, thediameter of the barrel is smaller than in the rear area of thecartridge. Live ammunition, the diameter of which is the same in boththe nose and the rear area, cannot be inserted into this barrel.

The firing functions are the same as described above; the mandrel, whichin the above design is inserted into channel 8, is not required withthis design. However, it is possible to use both mandrel and limit stopjointly. It is also possible, to provide a proprietary training barrelrather than modifying a barrel intended for live ammunition by adding aninsert. If flashes, smokes and bangs are not simulated, theaforementioned overflow channels in the gas choke can also be omitted,so that all the gas pressure is used to drive back the cartridge andrelease the weapon bolt.

There has thus been shown and described a novel training cartridge foran automatic rapid-fire weapon which fulfills all the objects andadvantages sought therefor. Many changes, modifications, variations andother uses and applications of the subject invention will, however,become apparent to those skilled in the art after considering thisspecification and the accompanying drawings which disclose the preferredembodiments thereof. All such changes, modifications, variations andother uses and applications which do not depart from the spirit andscope of the invention are deemed to be covered by the invention, whichis to be limited only by the claims which follow.

1. Medium-bore training cartridge for a medium-bore automatic rapid-fire weapon, said cartridge having a continuous central channel in a longitudinal direction of the cartridge having a forward region with an open front tip end and a rear region with a closed rear end, said channel accommodating a propellant charge and being closed at the rear end by a detonator charge for the propellant charge, said cartridge comprising, in combination: (a) a cartridge base; (b) a central barrel inserted into the base and forming the central channel with the cartridge base at the rear end; (c) an igniter cap inserted into the cartridge base for igniting the propellant charge; and (d) a single-piece cartridge body, which surrounds the central barrel from the cartridge base to the front tip end and which leaves the opening at the tip end.
 2. Training cartridge in accordance with claim 1, wherein the cartridge body is an injection-molded plastic component.
 3. Training cartridge in accordance with claim 1, wherein the cartridge base is a component made of a metal selected from the group consisting of aluminum and steel.
 4. Training cartridge in accordance with claim 1, wherein the central barrel is made of steel.
 5. Training cartridge in accordance with claim 1, wherein the central barrel has at least one of a gas choke and gas nozzle between the propellant charge and said open tip end.
 6. Training cartridge in accordance with claim 1, wherein the propellant charge is covered within the central barrel by a destructible cap.
 7. Training cartridge in accordance with claim 1, wherein the training cartridge has a smaller diameter in its forward region than in its rear region, whereby the two regions form a limit stop.
 8. System based on a training cartridge, which can be fired from an automatic rapid-fire weapon having a barrels which is geometrically designed such that live ammunition cannot be inserted into the barrel, said weapon being constructed such that after the training cartridge is ignited, pressure is created in the barrel, which guarantees the automatic function of the weapon as if firing live ammunition, the improvement comprising the training cartridge recited in claim 1, wherein said training cartridge and said barrel have corresponding means permitting only the training cartridge, and not live ammunition, to be inserted into the barrel; wherein the barrel includes an insert which essentially fills its entire cross-sectional area and which, when the training cartridge is inserted, provides a vacant space in front of the forward region of the cartridge into which the gases created by the propellant charge flow from the open tip end of the central channel; and wherein the pressure created in the vacant space pushes the training cartridge backwards towards a weapon bolt and out of the barrel, whereby the weapon bolt is re-tensioned.
 9. System in accordance with claim 8, wherein the insert includes a piston facing the training cartridge, which is fitted with a central mandrel and which projects into central channel of training cartridge inserted into the weapon.
 10. System in accordance with claim 9, wherein a gas choke is provided in the piston.
 11. System in accordance with claim 9, wherein the diameter of the central mandrel of the insert is smaller than the diameter clearance of the central channel of the training cartridge.
 12. System in accordance with claim 9, wherein the piston is arranged at one end of a tube to be inserted flush into the weapon barrel, whereby the tube has a flange-type limit stop facing outwards at an end opposite the piston and wherein a spigot nut with a central opening is provided to secure and hold the insert in position in the weapon barrel.
 13. System in accordance with claim 8, wherein the training cartridge has a corresponding limit stop in its nose area and the weapon barrel has a corresponding limit stop. 